Forget the grapefruit diet. Forget eating bacon and eggs but no bread. The best way to lose weight is not to eliminate foods, but simply to eat less altogether.

That is the conclusion of a new study published recently in the New England Journal of Medicine.

As long as you eat heart-healthy foods — such as less meat and more veggies, legumes and fish — in smaller portions, you don’t need to worry about percentages of fat, protein and carbs, say researchers.

“Diets … tailored to individual patients on the basis of their personal and cultural preferences may have the best chance for long-term success,” reported the authors.

The study, which was funded by the U.S. National Institutes of Health, took place at Brigham and Women’s Hospital in Boston and at Pennington Biomedical Research Center in Baton Rouge, La.

Here’s how the study was done: It enrolled 811 people between the ages of 30 and 70, and monitored them from October 2004 through December 2007. The subjects were all either overweight or obese — with a BMI between 25 and 40.

Participants were divided into four diet groups — one that received a low fat, average protein diet; one that received a low fat, high protein diet; one that received a high fat, average protein diet; and, finally, one that received a high fat, high protein diet. What the four diets had in common is that they were all low in calories (typically between 1,400 and 2,000 calories a day, depending on the size of the participant and their activity level).

All diets were also high in fibre, as well as being low in “bad” saturated fats. Participants were asked to exercise for 90 minutes a week, and all were offered regular counselling sessions.

It turned out that it didn’t matter which diet they followed, as results were similar for all four. On average, participants lost about 13 pounds over the first six months. After that, some weight came back, but after two years they had still lost an average of nine pounds and taken two inches off their waists.

The main message is that dieting should be simple, say the authors. All you have to do is choose healthy foods and minimize calories. Don’t worry about what percentage of fat, protein and carbs you are eating.

Authors called for improved disclosure of calorie counts in prepared foods.